While living in North America - Canada, I often come across the statement in the US ' We have eradicated Smallpox!' I was brought up with the knowledge that smallpox still exists in parts of the world and is only biding it's time to flare again.

In the 1960's it was in Stockholm and came from Africa. India is also a hot spot, so I understand.

My question is - is it gone from existence or if it is still around where is it and what is the likelihood of it becoming wide spread owing to the fact that immunisations are not being carried out everywhere?

Thanks for all you do, making it easy for everyone to understand what sometimes is gobbledegook to us laypeople.

Mankind has managed to eradicate smallpox apart from two stocks of it kept in "secure" research lab stores, one in the US, one in the former USSR, I think it's in Russia.If our politicians were as clever as our doctors and nurses then we would have destroyed it all.Unfortunately they are acting like 5 year olds. "I'm not giving it up until he has!"

Smallpox has no host apart from man, so once it's gone, it's gone. There's no scientific reason to keep it. We know the genome so, in principle, we could rebuild it if there were any need to (though I can't imagine why there might be). You don't need the virus to make a vaccine (you can use cowpox) and if we got rid of it there wouldn't be any call for the vaccine anyway.

If it were to escape (or be deliberately released) from those stores it would rip through the population. The lack of vaccination over the last decades would mean we would get a plague of biblical proportions.It would be interesting to see the politicians explaining "Well. we had to keep it because..."

Mankind has managed to eradicate smallpox apart from two stocks of it kept in "secure" research lab stores, one in the US, one in the former USSR, I think it's in Russia.

Yeah, but the Russian one wasn't there when the UN did a check. It was claimed it was moved from one institute to another and "lost" along the way. I forget the names of the research institutes now. It's quite well documented in the book "Biohazard" by Ken Alibek, former Deupty Director of the Russian Biopreparat.

Smallpox has no host apart from man, so once it's gone, it's gone. There's no scientific reason to keep it. We know the genome so, in principle, we could rebuild it if there were any need to (though I can't imagine why there might be). You don't need the virus to make a vaccine (you can use cowpox) and if we got rid of it there wouldn't be any call for the vaccine anyway.

In theory, it would be pretty easy. You wouldn't even have to use something as complex as cowpox. The vaccine was based on Vaccinia and this is currently used in loads of forms (usually expressing recombinant genes) as "Modified Vaccinia Ankara" in all sorts of new potential vaccines.There would be little to gain from doing it though...

If it were to escape (or be deliberately released) from those stores it would rip through the population. The lack of vaccination over the last decades would mean we would get a plague of biblical proportions.

Not really. The R0 of smallpox is pretty low so it's not that easy to spread, we have excellent treatments and an easy, fast, safe and efficacious vaccine at hand. Bear in mind that most natural smallpox cases aren't fatal (they are, however, disfiguring).It would be a problem in the immunocompromised populations, rather like TB is a major issue in HIV positive patients.It would also cause mass panic, but you hardly need to go to all that trouble to do that. Stick any white powder, maybe flour, in an envelope and post it to someone important and you'll do that.

Essentially all the data we have on the infectivity and mortality of smallpox is based on experience with populations which had already been exposed to it and/ or vaccinated.Today, very few people have any immunity, very few have been vaccinated and I rather doubt that there are stocks of the vaccine (why bother to clutter up the fridges with a vaccine for a disease that doesn't exist?)I rather suspect that an outbreak today would be a lot nastier than in the past, and it wasn't nice then.

Essentially all the data we have on the infectivity and mortality of smallpox is based on experience with populations which had already been exposed to it and/ or vaccinated.Today, very few people have any immunity, very few have been vaccinated and I rather doubt that there are stocks of the vaccine (why bother to clutter up the fridges with a vaccine for a disease that doesn't exist?)I rather suspect that an outbreak today would be a lot nastier than in the past, and it wasn't nice then.

Quite right! There are many people who were born since 1978 when the last case was treated. They would succumb quickly should it get loose again.

It's stored and used as an illegal bio weapon. It's spread by close physical contact.

In the western nations with excellent health control an outbreak would be quickly isolated and contained. In a third world nation the situation could and would be a very serious situation indeed.